Recently, provision of a mobile telephone service area that employs a small-scale base station called “femto-cell” is conceived. A “femto-cell” is generally formed by connecting a gateway for a femto-cell (FGW) installed on a mobile telephone service provider side and a small-scale base station for a femto-cell (femtocell Access Point (femtoAP)) by an IP broadband line such as an ADSL or an FTTH.
As femto-cell services, the provision of various services are considered including a low-priced flat-rate service by the mobile telephone service provider in addition to provision of a signal receiving environment that is better than that of a macro-cell, a high-speed data communication environment associated therewith, effecting improved efficiency of frequency usage by allowing a monopoly of specific users of frequencies.
In an environment having a broadband line, the femto-cell services can be easily adopted by merely connecting the environment to a femtoAP. A femtoAP is installed in the residence of a user who adopts the services. Therefore, it is expected that control by mobile telephone service providers will be mitigated such that the management restrictions imposed by the mobile telephone service providers will be mitigated and users will be able to freely move the location of and turn on and off the femtoAP.
Femto-cell services have a potential for realizing a communication link between an information terminal and home appliances in addition to provision of services associated with the above advantages. For example, communication between a personal computer (PC) and a mobile telephone is usually realized using a memory card, or a dedicated communication cable and software as a medium. However, the manipulation of inserting and pulling out a memory card or a communication cable is very troublesome for a user.
With the prevalence of broadband communication and the increase of content types and content sizes handled in recent years, data places a heavy burden on the memory of mobile telephones and cannot be completely stored in the memory when directly downloaded from, for example, a site on the Internet. Use of a mobile telephone as a music player is prevailing due to the integration of mobile telephones with a portable music player function, resulting in a demand for storage of music files downloaded at a fee.
On average, mobile telephone users purchase a new mobile telephone approximately every two years. However, to transfer files downloaded to the mobile telephone to a newly purchased mobile telephone, the user must transfer and store the files of the old mobile telephone on a PC and subsequently transfer the files later to the mobile telephone newly purchased. Therefore, increased simplification of the communication between the mobile telephone and the PC is demanded (see, e.g., Japanese Laid-Open Patent Application Publication No. 2007-282255).
“WiFi” (a wireless local area network (LAN)) is conceivable as an ordinary approach of communication between a mobile telephone and a PC; and a mobile terminal of a 3GPP scheme that includes the WiFi is actually exists. However, this dual terminal has a problem in terms of power consumption and price. Although the femto cell solves these problems, the wireless scheme that the femto cell supports includes only wireless schemes for mobile communication (for example, 3GPP).
However, for the femto-cell service, it is basically assumed that communication in a residence between a mobile communication network and a mobile terminal is realized through the femtoAP installed in the residence while the communication between a PC and the mobile terminal in the residence is not basically assumed. Therefore, a problem has arisen in that transmission of a packet from the PC to the mobile terminal in the residence is difficult.
For an ordinary femto-cell service, a mobile network-use address for a mobile terminal is assigned from a mobile communication network to the mobile terminal each time a data communication request is issued to the mobile terminal. Therefore, at the residence of a user, when the user tries to transmit a packet from a PC to the mobile terminal, the user cannot obtain the mobile network-use address assigned to the mobile terminal at that time.
Even if the PC is successful in obtaining the mobile network-use address assigned to the mobile terminal, when the PC transmits the packet using the mobile network-use address as the destination address of the packet, the transmitted packet arrives at the mobile terminal through the mobile communication network because, for example, according to the 3GPP, a tunnel is created between the femtoAP and the mobile communication network and, a communication path is formed between the femtoAP and the mobile terminal. Therefore, the communication resources of the mobile communication network are burdened and the time necessary for transmitting the packet from the PC to the mobile terminal becomes long.